Umm… it’s right there I believe?
Error: ReceivePossess: Override of UFUNCTION in parent class (Controller) cannot have a UFUNCTION() declaration above it; it will use the same parameters as the original declaration.
I guess your ReceivePossess has a UFUNCTION above it, which the build tool doesn’t like, as it wants to use the UFUNCTION definition used in Controller.
I believe you can simply fix it by removing your UFUNCTION definition.